Handle LED state sync entirely in Viewport

Apply workaround for FLTK's bad focus handling so that we can let
Viewport handle LED synchronisation without help from DesktopWindow.
diff --git a/vncviewer/Viewport.h b/vncviewer/Viewport.h
index 7acf348..14ef4ab 100644
--- a/vncviewer/Viewport.h
+++ b/vncviewer/Viewport.h
@@ -52,8 +52,6 @@
 
   // Change client LED state
   void setLEDState(unsigned int state);
-  // Change server LED state
-  void pushLEDState();
 
   void draw(Surface* dst);
 
@@ -83,6 +81,8 @@
   static void handleAltGrTimeout(void *data);
 #endif
 
+  void pushLEDState();
+
   void initContextMenu();
   void popupContextMenu();